The best age of children's orthodontics depends on their own growth and development and the types of children's malocclusion, which is mainly divided into three periods: deciduous teeth (3-6 years old): malocclusion of deciduous teeth or malocclusion (partial occlusion) should be corrected as soon as possible, which is beneficial to maxillary development and prevents permanent teeth from malocclusion. At this time, the child's permanent teeth have not erupted, and the roots of deciduous teeth have not been absorbed and are relatively stable. If the child has bad habits such as sticking out his tongue and biting his lips, it can be corrected at this stage to prevent malocclusion. It can be corrected by wearing oral orthosis, and the course of treatment is about 6 months. Early treatment is of great benefit to the normal development of children's maxillofacial region.

Mixed dentition (7 ~ 1 1 year): At this time, new permanent teeth begin to erupt, teeth grow rapidly and occlusion is unstable, which is the frequent period of tooth deformity. The main reason is that deciduous teeth fall off prematurely, which leads to the reduction of dental arch length, which in turn leads to the inability to arrange teeth. Such children should be regarded as gap holders. Early deciduous teeth fall off and close the gap, which leads to insufficient eruption space of permanent teeth and tooth deformity. Orthodontic appliances can be used to repair the dentition gap, and movable or fixed orthodontic appliances can be used to correct dentition in different degrees, even under the condition of external plastic force. Permanent tooth period (12 ~ 18 years old): all deciduous teeth have been replaced, and the second and third big teeth are in another rapid growth period. At this time, the diagnosis of tooth deformity is clear, and the correction is rapid and stable in this rapid growth period. In order to reduce the occurrence of tooth deformity, children's oral habits should be carefully observed. If children are found to have bad habits such as biting pencils, sucking fingers, biting lips and sticking out their tongues, they should be corrected in time. Because taking some simple treatments in the early stage can block the occurrence and development of deformity in a short time and achieve twice the result with half the effort. Orthodontic treatment of teeth can not only make children have charming smiles, but also prevent diseases such as gingival atrophy and loose teeth.